Utility lines for water, electricity, gas, telephone, and cable television are often run underground. In many situations, the underground utilities can be buried in a trench which is then back-filled. Although useful in areas of new construction, the burial of utilities in a trench has certain disadvantages. In areas supporting existing construction, a trench can cause serious disturbance to structures or roadways. Further, there is a high probability that digging a trench may damage previously buried utilities, and that structures or roadways disturbed by digging the trench are rarely restored to their original condition. Also, an open trench poses a danger of injury to workers and passersby.
The general technique of boring a horizontal underground hole has recently been developed in order to overcome the disadvantages described above, as well as others unaddressed when employing conventional trenching techniques. In accordance with such a general horizontal boring technique, also known as horizontal directional drilling (HDD) or trenchless underground boring, a boring system is situated on the ground surface and drills a hole into the ground at an oblique angle with respect to the ground surface. A drilling fluid is typically flowed through the drill string, over the boring tool, and back up the borehole in order to remove cuttings and dirt. After the boring tool reaches a desired depth, the tool is then directed along a substantially horizontal path to create a horizontal borehole. After the desired length of borehole has been obtained, the tool is then directed upwards to break through to the earth's surface. A reamer is then attached to the drill string which is pulled back through the borehole, thus reaming out the borehole to a larger diameter. It is common to attach a utility line or other conduit to the reaming tool so that it is dragged through the borehole along with the reamer.
Another technique associated with horizontal directional drilling, often referred to as push reaming, involves attaching a reamer to the drill string at the entry side of a borehole after the boring tool has exited at the exit side of the borehole. The reamer is then pushed through the borehole while the drill rods being advanced out of the exit side of the borehole are individually disconnected at the exit location of the borehole. A push reaming technique is sometimes used because it advantageously provides for the recycling of the drilling fluid. The level of direct operator interaction with the drill string, such as is required to disconnect drill rods at the exit location of the borehole, is much greater than that associated with traditional horizontal directional drilling techniques.
For boring, the drill is fitted with different tools (also referred interchangeably herein as bits, cutting tool, drill attachments, boring tools) depending on the underground conditions and the particular type of hole to be drilled. The cutting tools have different properties and require that the machine be operated differently. For efficient and effective drilling the machine parameters are adjusted in part based on the specific cutting tool attached to the drill string. For example, the maximum thrust applied may be different from one cutting tool to the next. Traditionally, operators need to be trained on each of the tools so that they can set the appropriate control parameters base on the selected tool. Since a number of control parameters correspond to each tool type, the operators often need to rely on reference books that they carry with them to the job site. In addition, operators typically need to be trained to collect key data from the job site manually. For example, if multiple holes need to be drilled at a single job site over an extended period of time, it may be desirable to track the performance and machine feedback during the drilling of the first holes so that the drilling of the later holes can be optimized. The present disclosure provides an improved horizontal directional drilling machine and related methods that address some of these issues.